The present invention relates principally to an ignition coil assembly to be arranged to be directly coupled to an ignition plug for internal combustion engines.
Such types of ignition coil assemblies generally comprise a central iron core constructed by placing silicon steel plates one upon another so as to form the outer shape to a square pole configuration such as is disclosed in the Japanese Patent Provisional Publication No. 63-132411. There is a problem which arises with the aforementioned conventional ignition coil assembly comprising the central iron core with a square pole configuration, however, in that difficulty can particularly be encountered to encase it in a space such as a cylindrical plug hole for insertion of the ignition plug.